Help me to bring this Neo Geo AES to life!

I never had a neo geo AES, this is the first one in my life!

I always saw this gem in video game stores and it was my consume dream now 10-15 years later it became reality! But to avoid paying a fortune I bought it broken.

Here are pictures of the system and the power supply.

Here are pictures of the system and the power supply.




I found this RF genesis cable on my stuffs for testing.


This is the the plug


And this is the problem the AES has:


Any ideas of a fix?

 

PLEASEEEEE resize and thumbnail the photos, some of us use netbooks (1024 x 600).

Either your TV isn't exactly tuned to the RF channel or the NG isn't outputting a valid sync signal.
Perhaps the RF modulator is not receiving power, I'm not sure if the NG outputs +5V on the same pin as MD...

You need to address this or get a composite video cable for a clear video signal before any real diagnosis can be made.

 

Sorry for the pictures, I'll fix that when I get home.

I don't think the problem is in the RF cable because the seller who have an AV cable said this problem occurred with him. That's why he sold the AES.

Changed pictures size, hope this helps you guys to help me here, please

 

The LSPC (Line SPrite Controller) chip of the NEOGEO has a issue with the randomness of it's registers status during boot and it affects the output of sync, causing that fuzziness on the image. If you pay attention to the image and ignore the fuzziness you will notice that the image is composed of multi colored blocks (mostly red and white) and I believe that's garbage data on the video ram.

Point is: The CPU isn't starting but the graphics hardware is.

I am not sure if AES has the watchdog timer enabled, but if it has, that image should be blinking, meaning the system is resetting trying to start.

What happens when you turn it on without a cart ? (the colors of the screen have a meaning)

 

Typically the randomness at start is FIX layer garbage, this doesn't look like that to me, it almost looks like the game is running. Also as long as the LSPC is clocked it will generate sync so even if the CPU is down the image will be stable; I don't think the H and V counters are affected by reset. Plus I think there IS some sort of sync (even if invalid) or the TV would probably blank the screen, that's why it looks like there's something with the RF modulator.

 

If I left that fuzziness going it will act with a pattern. This is the game running for sure.
I'll open the console later today and post pictures of it.

 

What I said only apply for the first power up as the LSPC registers have unknown/random/glitched values on them. :shrug:

So because the MVS has a "proper bios" with test software built in it aways set up the LSPC completely and you get a solid image on every boot (it should show the test grid for the monitor and react to button presses on the joy buttons)

On such a early MVS the bios has some glitches and sometimes a perfectly healthy MVS does that when without a cartridge (I'm referring to the picture fuzziness) ...

 

Today I saw that the fuzziness is just fuzziness. The game isn't working

Without cartridge I get red screen this means



Blue: All tests passed (The AES does not test the Z80 sound IC).
Red: Work RAM error ($100000 region).
Green: Palette RAM error ($400000 region).
Yellow: Video RAM error (programmed through custom port).
Pink: BIOS checksum error (0xC00000 region).
Cyan: Memory card error (only tested if card in unit and blank).

So I opened it up and here it is

http://i.imgur.com/CF8sm.jpg

I'll not put it here and leave the link so the picture can be seen bigger and not harm the forum.

The strange part is this


Any ideas?

 

Replace the WORK RAM chips :3

The crystal and wires are a modification for the PAL-M video standard. :thumbsup:

 

Why would you ever use an RF adapter on a Neo Geo AES?

 

Because that's the only thing I have in my hand right now.
It was for testing purpose only.

BTW, I'm going to ship it to l_oliveira, if he can bring this AES to life again he'll be a wizard of electronics.

 

Your power supply is of the wrong polarity, the AES needs tip negative. If you have a model 1 Mega Drive/Genesis power supply, use that instead. Hopefully the wrong power supply didn't cause too much damage to the AES...

 

It's a 5V AES, it's the correct supply....

Before the WRAM is replaced I'd really check the traces, chip death is really rare.

 

Don't the 5V AESes also have tip negative polarity? The voltage and amperage are correct but the polarity is mixed up on his power supply.

 

Yeah, that's why I'm sending to l_oliveira. He lives in Brazil too and is by far a better solderer them I'm.

I don't have a heat gun to work in such small chips. I think everything here is related to bad traces or some dry connection somewhere. The sad part is that it's very hard to fix and very hard to see.

 

If the polarity was wrong (oh please this is Brazil, DO NOT TRUST THE STICKER :lol either the NEO GEO would be completely ruined and no Sync/colorful blocks/colored screens would show or the power supply would be shorted out from overcurrent. :thumbsup:

 

I told you already that I repaired a few hundreds of MVS boards and that is just a bad joke of a repair for me. Should be up and running within minutes it's out of the mailbox. Just like the PS2 you sent me last time... :thumbsup:

(I feel a bit bad on that one because I instigated you to remove the mod chip you had on it, though ... :lol